Field of the Invention
The present invention relates to a resistor and a manufacturing method thereof, and more particularly to a resistor having improved joining strength and durability, since a ceramic tube formed of a ceramic material is used and the ceramic tube is joined to sealing electrodes by use of brazing rings, and stably used at a high voltage due to excellent heat dissipation characteristics, and a manufacturing method thereof.
Description of the Related Art
In general, a resistor that is used in a circuit to restrict the flow of current causing a drop in voltage is a device consuming power to produce heat. A maximum power consumed thereby is set as the rated power. Resistors commonly used in electronic circuits have a power rating of about ⅛ to about ½ W, and resistors with a high power rating are used in power supplies.
FIG. 10 is a sectional view illustrating a conventional resistor. The conventional resistor includes a coil 2 wound on a cylindrical body 1 formed of glass fiber and having a predetermined length, cap bodies 3 disposed at both ends of the cylindrical body 1 provided with the coil 2 wound thereon and formed of a conductive material, and lead wires 4 connected to the cap bodies 3. In addition, both ends of the coil 2 are electrically connected to each of the cap bodies 3.
Then, the coil 2 and the cylindrical body 1 are coated with various colored synthetic resins indicating predetermined standards, and the resistor is commercialized. The resistor having the above described structure may be used in an electronic circuit when the lead wires 4 are inserted into slots of a printed circuit board in a fixed state.
Meanwhile, Korean Patent Application Publication No. 1999-0040562 discloses a coated parallel resistor including a first coil and a second coil.
However, power greater than the rated power supplied to conventional resistors generally causes deterioration in the resistors due to heat, thereby causing damage thereto. In particular, carbon resistors are easily damaged by heat, brining damages to electronic circuits. In addition, as ambient temperature of the resistor increases, heating of a resistive body needs to be reduced. Thus, the resistor needs to be used at a lower power than the rated power. As resistance increases, noise generated in the resistive body increases. In order to obtain high resistance while generating low noise, a fine coil needs to be wound or a thin metal film needs to be. However, in this case, a cut-off may easily occur.